Energy scaling of the product state distribution for three-body recombination of ultracold atoms
Energy scaling of the product state distribution for three-body recombination of ultracold atoms
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DOI：
10.1103/physrevresearch.5.013161
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发表时间：
2022-11
影响因子：
4.2
通讯作者：
S. Haze;J. D’Incao;D. Dorer;Jing-Lun Li;M. Deiss;E. Tiemann;P. Julienne;J. Denschlag
中科院分区：
文献类型：
--
作者：
S. Haze;J. D’Incao;D. Dorer;Jing-Lun Li;M. Deiss;E. Tiemann;P. Julienne;J. Denschlag
三体重组是一种化学反应，其中三个原子的碰撞导致双原子分子的形成。在超冷状态下，预计分子的生成速率通常会随着结合能的降低而降低，然而，其精确的依赖关系和控制它的物理原理到目前为止还不清楚。在此，我们对超冷Rb三体重组的能量依赖进行了全面的实验和理论研究。为此，我们以状态到状态的分解方式确定了分子的生成速率，结合能E_b$的范围从0.02到77 GHz$\乘以h$。我们发现形成速率近似为$E_b^{-\alpha}$，其中$\alpha$在1附近。对于不同的分子产物的旋转角动量，除了可能的离心势垒抑制低结合能外，形成速率通常仅在两个因子内变化。除了三体数值计算外，我们还提出了一个微扰模型，揭示了形成速率能量标度的物理起源。此外，我们表明标度定律可能普遍适用于广泛的相互作用势。
Three-body recombination is a chemical reaction where the collision of three atoms leads to the formation of a diatomic molecule. In the ultracold regime it is expected that the production rate of a molecule generally decreases with its binding energy $E_b$, however, its precise dependence and the physics governing it have been left unclear so far. Here, we present a comprehensive experimental and theoretical study of the energy dependency for three-body recombination of ultracold Rb. For this, we determine production rates for molecules in a state-to-state resolved manner, with the binding energies $E_b$ ranging from 0.02 to 77 GHz$\times h$. We find that the formation rate approximately scales as $E_b^{-\alpha}$, where $\alpha$ is in the vicinity of 1. The formation rate typically varies only within a factor of two for different rotational angular momenta of the molecular product, apart from a possible centrifugal barrier suppression for low binding energies. In addition to numerical three-body calculations we present a perturbative model which reveals the physical origin of the energy scaling of the formation rate. Furthermore, we show that the scaling law potentially holds universally for a broad range of interaction potentials.